gearing



(No Model.) 2 Sheets-Sheet 1.

P. B. RAE.

GEARING.

No. 431,124. Patented July'l, 1890.

0 WI TJvESAS i q/lm IN VEJVTOR WM 21 6 Attorney r (No Model.) 7 2 Sheets-S1ieet 2.

F. B. RAE. GEARING.

No. 431,124. Patented July 1, 1890.,

IHIII lllllllll mun-J WITNESSES [NVENTOB UNITED STATES PATENT OFFICE.

FRANK B. RAE, OF DETROIT, MICHIGAN, ASSIGNOR TO THE DETROIT ELECTRICAL WORKS, OF SAME PLACE.

GEARING.

SPECIFICATION forming part of Letters Patent No. 431,124, dated July 1, 1890. Application filed May 6, 1889- Serial No. 309,841. (No model.)

To all whom it may concern.-

Be it known that I, FRANK B. RAE,- a citizen of the United States, residing at Detroit, county of, Wayne, and State of Michigan, have invented a certain new and useful Improvement in Gearing for Electric Motors and other Purposes; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

. My invention relates to a system of gearlng for transmitting motion from the primal source of power to one or more movable parts,

and more particularly is designed for use in connection with electric motors geared to and arranged to propel the driving-wheels of a traveling vehicle.

In ordinary systems of electric-railway locomotion, where the electric motor is mounted upon the vehicle and has its armature mechanically connected with the driving-wheels of said vehicle by some approved manner of gearing, it is desirable and necessary in prac tice to devise means whereby there may be an initial yielding impact or pressure between the revolving armature and the instrumentality to which it communicates its rotary motion, so that when the armature, which quickly responds in its velocity of rotating to the actuating electric current, it may gradually and in a less rapid manner transmit its power to the vehicle without a sudden jerk, strain, or pull, whichinevitably shatters and weakens the several co-operating parts, injuring, if not entirely destroying, the intermeshing teeth of the gearing, besides disturbing the comfort and equilibrium of the passengers or occupants of the motor-vehicle. Therefore my invention consists, in brief, of an improved form of spring-gearing, by means of which the motion of the armature is received and gradually taken up, to a certain extent at first, before such rotary pressure is transmittedv in full to the adjacent rotary part in the train of gearing; or, in other words, my invention comprises a device for maintaining for a certain predetermined times a variable leverage or speed ratio between the armature-shaft and the driving wheels of the vehicle, whereby the sudden impetus of the armature is gradually transmitted to the driving-wheels.

Referring to the accompanying drawings, Figures 1 and 2, respectively, are views in side elevation, showing diiferent faces or sides of my improved gear-wheel with the outer plates removed to show the form and manner of attaching take-up springs. Fig. 3 is a central vertical transverse section, and Fig. 4 is a plan View illustrating the employment of the gear with an electrically-propelled vehicle.

Like letters of reference mark like or corresponding parts in the several views of the drawings.

Referring to Figs. 1, 2, and 3, A designates the body of the gear-wheel, consisting of the toothed tread or periphery a and the web I). The web 12 is centrally provided with a circular perforation or orifice 6, designed to receive and accommodate the hub C, (shown therein,) and c designates a boss or flange formed integral with theweb b and extending out in a horizontal plane at right angles with the perpendicular plane of the web, on each side of said web a slight distance, as shown clearly in Fig. 3. Thus it will be understood that the length of the hub-orifice e is equal to the thickness of the web 1) plus that of the two bosses or flanges c c.

On the interior circular wall of the orifice c and diametrically opposite each other ape located two radially-projectinglugs D D, each extending inwardly and having its inner face con'caved to conform to the convex exterior of thehub C, and its sides bounded by radii of a circle whose center is the center of the orifice c.

The hub C is designed to fit loosely in its seat in the orifice e, and is of the usual construction, with the exception that its exterior circular surface is provided with two lugs D i lugs D D, respectively, between lugs D D, the said lugs D D are free to oscillate back and forth in the space intervening between the lugs D D, which space is greater than the width of the lugs D D.

E E severally represent two spiral springs, of the desired size and shape to insure strength and elasticity, placed within the side plates F F of the wheelA, and thereby protected from dirt, dust,m1 1d, and other foreign substances. The spring E at one end works loosely over and is guided and supported by the stud g, attached to and. projecting from the face of the web (9, near the periphery of the wheel. It is then coiled helically in the direction of the arrow, Fig. 1, and has its other extremity fastened rigidly to the hub O. The other spring E (shown on the other side of the web I) in Fig. 2) is similarly arranged and secured, but is coiled in an oppositedirection and sofastened to the hub C that when the spring E is compressed the spring E will be expanded, and vice versa.

It will be understood that there is sufficient lateral space between the web I) and the plates F F on each side to accommodate and receive each spring E or E and to permit their contraction and expansion.

The lugs D D of the hub O are held in their proper position in the orifice 6 against lateral displacement by the guard-plates G G, each of which latter has a central circular perforation for the hub O and a diameter equal to the diameter of the orifice 6, plus the vertical thickness of either flange or boss 0. Each plate G or G is bolted to the flange c by bolts ff. (See Fig. 3.)

The side plates F F are similar in construction and arrangement to the guard-plates G G, but have a larger diameter and are secured to the web 1), near the periphery of the wheel A, by the bolts g g.

Referring now to Fig. 4, H designates a suitable motor-frame; I, an electric motor of any desired size and type; J, the armatureshaft of said motor; K, a pinion on said shaft J; A, the spring gear-wheel; L, the shaft for the gear A; M, the pinion meshing with the spur-wheel N on the axle O, which carries the driving-wheels P P of the vehicle. WVhen the armature-shaft J is given a sudden impetus by the closure of the motorcircuit, (not shown,) the pinion K receives the same'initial velocity as the shaft J and tends to transmit motion in the same ratio to the gear A; but as the periphery of the gear A begins to revolve in response to the actuating-pinion K it fails to proportionally rotate its hub C, because it must first exercise sufficient rotary motion to wind the spring E or'E, as the case the hub-(J is decreased to such an extent as to revolve the hub C in the same ratio as the periphery of the gear A; or, in other words, the gear A can exercise its rotary tendency on spring E E without revolving the hub C in unison a distance equal to the oscillatory play of the lugs D D between the lugs D. From this explanation it becomes manifest thatthe starting of the car will 'be gradual and uniform, even though the initial impetus of the propelling power (armature-shaft) is very sudden. On the other hand, it will also be understood that a sudden reversal of the direction of rotation of the armature-shaft will be communicated gradually to the driving-wheels through the agency of the remaining spring E or E, which in this event will be fully unwound when the first spring is fully compressed. It will also be manifest that when this gearing is used in connection with an electromotor the elastic gear permits the motor-armature to commence revolving before the entire load of the vehicle comes upon it, so that a counter electro-motive force would be developed in the armature coincident with putting on. the current, so that excessive flow through the dead resistance of the armature, which would result if the armature had to operate directly upon the heavy load of the vehicle, is prevented. This is a well-known disadvantage in the use of electromotors for propelling vehicles, as the cur- .rent is liable to flow through the armature in such excessive quantities as to cause injury thereto and before the armature has time 3 to move, and thus generate a counter electromotive force to prevent such dangerous currents. 7 I

I desire to-here call attention to the fact that the variability of the speed ratio can be difierentiated at will by multiplying the number and location of the spring-gears.

All the parts of my invention are strong, durable, and interchangeable, and by utilizing the said invention for the purpose described the wear and tear of the gears, bearings, shafts, and motor are decreased, the

waste of current in the motor lessened and the comfort of the passengers promoted.

Having thus fully described my invention,

' what I desire to secure by Letters Patent is 1'. A gear-Wheel comprising aweb having a toothed tread or periphery and a hub-seat provided with limiting-lugs, an independent- .ly-movable hub, also provided with limitinglugs placed in operative relation to those of a the web, and one or more springs loosely .connected atone end to the web and rigidly at the other to the hub.

2. A gear-wheel comprising a web, an independentlymovable hub, guard plates for holding the hub in its seat, one or more springs mechanically connecting said web and :hub, and side plates secured to the web and protecting the spring or springs.

may be, up until its elasticity of impact on In testimony whereof I have hereuntoset my hand this 2d day of May, A. D. 1889.

FRANIQ B. RAE. \Vitnesses:

F. P. HILL, F. D. LEMPKE. 

